<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1">
<title>Tutorial: logP(CO2)=const</title>
<style type="text/css"> <!-- @import url(1_.css);   --> </style>
<link disabled rel="stylesheet" type="text/css" href="1_.css">
</head>

<body bgcolor="#ffffff" text="#000000" link="#008000" vlink="#008000" alink="#008000">
<table cellspacing="0" cellpadding="0" border="0">
  <tr>
    <td align="center" valign="middle" width="50">
    <a href="0_Index.htm"><img src="images/thco35_s.gif" border="0" width="32" height="32" alt="Chem.Eq.Diagr"></a>&nbsp;</td>
    <td align="left" valign="middle"><font size="-1"><a href="0_Index.htm">Chemical Equilibrium Diagrams</a>&nbsp;/ <a href="Tut_0_Tutorials.htm">Tutorials</a></font></td>
  </tr>
</table>

<h3>Make diagrams for constant gas pressure:</h3>
<h3>log <i>P</i><sub>CO<sub>2</sub></sub> = constant</h3>

<p>Follow these simple steps:</p>

<p><b>1)</b> Start <a href="DB_0_Main.htm">DATABASE</a> and click on &#147;C&#148;
(carbon) in the periodic table. Click on <nobr>&#147;CO3 2&#8722;&#148;</nobr>
in the list of available components. Both &#147;H+&#148; and
<nobr>&#147;CO3 2&#8722;&#148;</nobr> will be
listed as selected components. Click on the pull-down menu
<nobr>&#147;File&nbsp;/</nobr> Save and <nobr>Exit&#148;.</nobr>
Click on the SPANA button to save the data file and to make a diagram.
Enter a file name, for example <nobr>&#147;<tt>CO3 2-</tt>&#148;.</nobr></p>

<p><b>2)</b> The <a href="S_0_Main.htm">SPANA</a> main window will
appear. Diagrams made with these chemical components <nobr>(H<sup>+</sup></nobr>
and <nobr>CO<sub>3</sub><sup>2&#8722;</sup>)</nobr> would have a
total concentration for carbonate (<a href="SP_Diagr_Log.htm">example</a>
with <nobr>[CO<sub>3</sub><sup>2&#8722;</sup>]<sub>T</sub></nobr> = 10 mM).
A diagram for constant <nobr>log<i>P</i><sub>CO2</sub></nobr>
requires that <nobr>CO<sub>2</sub>(g)</nobr> is one of the chemical components.
It is necessary to <a href="S_Modify_Chem_System.htm">exchange
a component with a reaction products.</a></p>
     
</p>Click on the pull-down menu <nobr>&#147;Run&nbsp;/</nobr>
Modify chemical <nobr>system&#148;.</nobr> The &#147;modify&#148; window appears.
Click on <nobr>&#147;CO3 2-&#148;</nobr> to select it. Click on the 
&#147;Exchange&#148; button:
<img src="images/exchange.gif" alt="Exchange button" title="Exchange button" align="texttop" height="37" width="37" border="0">
</p>

<p>A new window will appear listing the available reaction products. Click on
<nobr>&#147;CO2(g)&#148;</nobr> to select it and on the OK-button.
Back on the &#147;modify&#148; window click on the &#147;Save changes and exit&#148;
button. Give a name for the new data file, for example <nobr>&#147;CO2(g)&#148;.</nobr>
</p> 

<p>Back on the SPANA main window: click on the pull-down menu
<nobr>&#147;Run&nbsp;/</nobr> Make a <nobr>Diagram&#148;.</nobr>
A new window appears to select what type of diagram is wanted.
Click on the Diagram button in the upper-left corner of the window.</p>
<p>
<center><img src="images/Make_diagr.gif" alt="Diagr_Button" title="Diagr_Button" height="67" width="64" border="0"><br clear="all"></center>
</p>
<p>The calculations will be done by a console program.
When the calculations are finished the diagram is displayed in a window:</p>

<p>
<center>
<img src="images/Diagr_LogCO2.gif" alt="Diagr LogCO2" title="Diagr LogCO2" height="214" width="307" border="1">
</center>
</p>

<p>Compare this diagram with that <a href="SP_Diagr_Log.htm">obtained when
<nobr>CO<sub>3</sub><sup>2&#8722;</sup></nobr>
is a component</a> instead of <nobr>CO<sub>2</sub>(g).</nobr></p>

</body>
</html>